Touch sensors are known in the art for controlling devices via a user interface or a man machine interface. Traditionally, touch sensors are adapted to detect a touch position in a two-dimensional way. Especially consumer products, for example mobile telephones, mobile navigation systems, mobile gaming devices and mobile media players, are looking for new input methods for utilizing more complex applications. Therefore, the third dimension for input purposes is utilized. Utilizing the third dimension can be realized for example by sensing a force being applied by user on a touch panel in a direction perpendicular to the plane of the touch panel. Thus, the first and the second dimensions are sensed by a touch position on the touch panel and the third dimension is sensed by the force being applied at the touch position.
For example, WO 2010/091744 A1 discloses a sensor, a display including a sensor, and method for using a sensor. The sensor comprises a membrane including a pattern of electrically conductive material. Furthermore, the sensor comprises a capacitance measuring unit configured to detect the presence of a finger, hand, or other object on the sensor or in the vicinity thereof. Furthermore, the sensor comprises a resistance measuring unit configured to detect whether a force is exerted by the finger, hand or other object on the sensor. The electrically conductive material comprises indium tin oxide (ITO) as it provides a piezoresistive property and is conducting and transparent. However, it may be brittle and may crack and is furthermore expensive due to the cost of indium.
Furthermore, on a front side of many consumer products comprising a touch sensitive surface, a lot of components should be grouped together, for example a camera, a loudspeaker, an ambient light sensor, a proximity sensor and so on. This may disturb a clean design of the front side of the consumer product, especially when these components are to be integrated in a mobile phone.
Therefore, there is a need to provide a more robust and cost efficient sensor to be used at for example a front side of a consumer product, especially a mobile phone.